Construction of NiCoP-NiCoO/NiCo–PO heterostructure by controllable phosphating effect for high-performance hybrid supercapacitors and alkaline zinc batteries

Heterostructures are enriched with interfacial effects from the separated materials with different chemical properties and crystal phases, which can be used to design advanced materials with novel properties. Besides, high-performance electroactive materials are still urgently needed for both hybrid supercapacitors (HSCs) and alkaline zinc batteries (AZBs), while single phase materials cannot meet comprehensive performance requirements of high-capacity, high-rate performance, and long-term cycling stability. Here, NiCoP-NiCoO2/NiCoPOx heterostructure is designed to achieve enriched interfacial effect between crystallized phosphides and amorphous phosphates. Our heterostructure is transformed from Ni1.5Co1.5O4 which is phosphatized using NaH2PO2·H2O, while this conversion method creates a great amounts of high-crystallized NiCoP nanoparticles which distributed in an amorphous NiCoPOx matrix. The heterostructure exhibits a high capacity of 177.0 mA h g–1 at 1 A g–1 and a high capacity retention of 125.0 mA h g–1 at 50 A g–1, combined with 78.7% of capacity retention after 10,000 cycles. More significantly, NiCoP-NiCoO2/NiCoPOx heterostructure can be used as the cathode material for both HSCs and AZBs, and its excellent performance results in both high-energy and high-power performances in above two-type devices. Our investigations demonstrate excellent performance from the interfacial effect of our heterostructure, and give some insights to design advanced materials for energy storage applications.